This Sept. 15 image purports to show smoke rising over Camp Bastion in Helmand Province, Afghanistan, after what a Taliban media unit said was an attack at the base. / SITE Intel Group via AP

by Jim Michaels
USA TODAY, USA TODAY

by Jim Michaels
USA TODAY, USA TODAY

The Taliban terrorists who pulled off one of the most damaging attacks of the Afghanistan War were probably trained for the plot in Pakistan, illustrating how the U.S. ally threatens to jeopardize a successful withdrawal, military experts say.

The attack on the heavily defended Camp Bastion in Helmand province destroyed six U.S. aircraft and killed two Marines on Sept. 14. One of the attackers survived and has revealed that he received some of his training for the plot in Pakistan, a senior U.S. military official told USA TODAY. The official requested anonymity because of the sensitivity of the issue of U.S.-Pakistani relations.

The Pentagon has long complained to the Pakistani government and military about sanctuaries in Pakistan that put Taliban leaders outside the reach of the U.S. military. The latest intelligence on the Camp Bastion attack shows little has changed, experts say.

"Unless the Pakistanis do more about those insurgents crossing the border into Afghanistan, you're going to have a critical security challenge," said Mark Jacobson, a former NATO official in Afghanistan at the German Marshall Fund. "It makes the situation post-2014 more precarious than it would be otherwise."

Most U.S. combat forces will withdraw from Afghanistan at the end of 2014. U.S. and Afghan officials are negotiating over a residual force that would stay behind for counterterrorism missions and support for Afghan security forces.

Coalition and Afghan forces have weakened the Taliban throughout southern Afghanistan, and the group's financing and leadership inside Afghanistan have been devastated, according to NATO. However, many Taliban leaders remain safely in Pakistan, and fighters regularly slip cross the border to launch attacks.

"It was months in the planning," Gurganus said. "This was not a bunch of local yahoos who were just thrown together and said, 'Hey let's go attack Camp Bastion.'"

Camp Bastion is part of a sprawling coalition complex in Helmand province; its security is the responsibility of British forces. On a moonless night, the insurgents used seven bolt cutters to open a hole in a perimeter fence.

Dressed in U.S. military uniforms, they split into three five-man teams and used a dry streambed to creep toward the flight line in sight of guard towers, armed with assault rifles, rocket-propelled grenades and machine guns.

They were able to keep up a nearly four-hour firefight, destroying six Marine AV-8B Harrier jets, damaging two others and three refueling stations, sending flames high into the air. A coalition counterattack killed all but one of the insurgents.

The jets cost $24 million apiece, and total damage to the base was estimated at $200 million, according to Arizona Sen. John McCain, ranking Republican on the Armed Services Committee. He called the attack "perhaps the most brazen and least-reported attack this year."

The dead insurgents had spray-paint residue on their faces, suggesting they used the spray as an inhalant to deaden their senses and get them high for a suicide mission.

"They came here prepared to die," Gurganus said.

More than 100 servicemembers responded to the attack, using numerous weapons at the base, including a machine gun taken from the rear of an Osprey, a tilt-rotor aircraft. Helicopter gunships fired hundreds of rounds at insurgents from the air.

One of the Marines killed in the attack was the Harrier squadron commander, Lt. Col. Christopher Raible. He helped lead the counterattack, charging at the insurgents with only his sidearm, McCain said.